Bibcode
Rozas, M.; Richer, M. G.; López, J. A.; Relaño, M.; Beckman, J. E.
Bibliographical reference
Astronomy and Astrophysics, Volume 455, Issue 2, August IV 2006, pp.549-559
Advertised on:
8
2006
Journal
Citations
13
Refereed citations
11
Description
We analyze the broad, low intensity, high velocity components that are
seen in the Hα line profiles for a sample of HII regions. These
HII regions are chosen from among the brightest and most isolated in a
sample of spiral galaxies for which we have photometric and
spectroscopic data: NGC 157, NGC 3631, NGC 6764, NGC 3344, NGC 4321, NGC
5364, NGC 5055, NGC 5985, and NGC 7479. We confirm that the line
profiles of most of these bright, giant extragalactic HII regions
contain broad kinematic components of low intensity, but high velocity,
that we denote as wings. We analyze these components, deriving emission
measures, central velocities, and velocity dispersions of the blue and
red features, which are similar. We interpret these components as
expanding shells within the HII regions and produced by the stellar
winds from the ionizing stars. We compare the kinetic energies of these
expanding shells with the kinetic energy available from the stellar
winds. If we allow for the hypothesis that the brightest HII regions are
density bounded, we show that, for these HII regions, the stellar wind
mechanism can explain the observed shell kinetic energies.